161605605 has 32 divisors (see below), whose sum is σ = 296275968. Its totient is φ = 73684800.

The previous prime is 161605579. The next prime is 161605643. The reversal of 161605605 is 506506161.

It is not a de Polignac number, because 161605605 - 2¹¹ = 161603557 is a prime.

It is a super-2 number, since 2×161605605² = 52232743134832050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43470 + ... + 47040.

It is an arithmetic number, because the mean of its divisors is an integer number (9258624).

Almost surely, 2^161605605 is an apocalyptic number.

161605605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161605605 is a deficient number, since it is larger than the sum of its proper divisors (134670363).

161605605 is a wasteful number, since it uses less digits than its factorization.

161605605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4017.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 161605605 is about 12712.4193212779. The cubic root of 161605605 is about 544.6934336242.

The spelling of 161605605 in words is "one hundred sixty-one million, six hundred five thousand, six hundred five".